Abstract
As radiation due to radioisotope decay is discontinuously emitted, its data analysis can be done very easily by digital method. So it was rather early that a computer was applied in the field of nuclear medicine using radioisotope. Especially the processing of storage, calculation and display for radioisotope image data obtained by a scintillation camera and scanner was studied using a computer system.
In order that processed images might become useful in clinical routine, an online computer system is indispensable which could obtain results at real time.
Then we studied how much scale computer should be installed in an on-line system according to memory capacities and display resolution.
An ideal plan should be on-line connecting with an image memory unit, a central processing unit and a display unit each other and of being controlled each part of them by the computer as a central processing unit. But at the present time, either a mini-computer or a small hard program computer is used both a memory unit and a processing unit. Memory capacities for calculation depend upon the purpose of processing but 8 kilo words were enough for complicated calculation. And as the capacities for the data storage 16-20 kilo memory elements (about 8 bits/element) were needed, and 5×104 counts or so must be accumulated to make an image.
Also as the numbers of display points in an image using cathod ray tube (CRT) 16-100 kilo points might be necessary for a fine grain and continuous display according to a size of a spot on the CRT used now. For the purpose of increasing display points, it was considered as a reasonable solution to use an interpolation method instead of expansion of expressive magnetic cores.
